Retarding device for plunger-elevators.



JOHN. RETARDING DEVICE FOR PLUNGER ELEVATORS. APPLICATION FILED NOV. 16,1904.-

Patented Mar. 7, 1911.

lNVENTOR THE NORRIS PETIRS 011., WASHINGTON D c GRIFFITH JOHN,

IINITF sra'rns ngnnr orrien.

OF YONKERS, NEW YORK, ASSIGNOR TO OTIS ELEVATOR COMPANY,

OF EAST ORANGE, NEW JERSEY, A CORIORATION OF NEW JERSEY.

RETARDING DEVICE FOR PLUNGER-ELEVATORS.

esaeea.

Specification of Letters Patent.

Patented Mar. 7, 1911.

Application filed November 15, 1904. Serial No. 232,856.

To all whom it may concern:

Be it known that I, GRIFFITH JOHN, a subject of the King of GreatBritain, and a resident of Yonkers, in the county of VVestchester andState of New York, have invented oertain new and useful Improvements inRetarding Devices for Plunger- Elevators, of which the following is aspecification.

My invention relates to retarding devices for plunger elevators and itsobject is to provide means for overcoming the momentum of suchelevators.

Like characters of reference designate corresponding parts in all of thefigures, in which Figure 1 shows in side elevation a plunger elevatorembodying my invention. A part of this figure is shown in section. Fig.2 is an enlarged plan view of a part of the apparatus which I use. Fig.3 is a sectional view of an auxiliary valve which I use in carrying outmy invention. Fig. 4 is a plan view partly in section of a part of myapparatus. Fig. 5 is a sectional view of a modification of a part of themechanism which is shown in Fig. 4.

Referring now to the drawings, 10 designates an elevator car which isattached to the top of a plunger 11.

12 is a hydraulic cylinder into which the plunger 11 runs through acylinder head and stuifing box 13. A rope or cable 14 is attached to thetop of the car and runs up over a sheave 15 which is situated at the topof the elevator hatchway. The rope or cable 14 passes over this sheaveand down to a counterweight 16.

In the car 10 is placed an operating lever 20 which is arranged to movetilting sheaves 21, 21. Two operating ropes 22, 22 are attached tofixtures 23, 23 at the top of the hatchway and descend to a point nearthe bottom of the hatchway where they pass under a pivoted segment 24 towhich they are attached. Between the supports at the top of the hatchwayand the segment 24 they pass over the tilting sheaves 21, 21.

3O designates a main or reversing valve which is connected to thecylinder head 13 below its stufling box by a pipe 33. This valve isarranged to close the ports leading to the pipe 33 or to open them sothat they afford communication between it and either the pipe 31 or thepipe 32. These pipes 31 and 32 are connected respectively to a source ofhydraulic power and to an exhaust. A pilot valve 50 is situated nearthis main or reversing valve and is connected in the usual manner bypipes, which are not shown, to the main valve in such a way thatwhenever its valve stem 51 is manually moved it will cause the stem 34of the main valve to have a movement corresponding to that which isgiven it by hand. The valve stem 34 of the main valve is connected to anarm 35 which is attached to the stem 51 of the pilot valve by means of aconnecting link 52 and is also connected to the pivoted segment 24 bymeans of a connecting rod 53 and a lever 25 which is rigidly connectedto the pivoted segment 24. By means of this arrangement the main valve30 may be controlled by the operator in the car. Whenever he moves thelever 20 to the left or to the right, he thereby moves the stem 51 ofthe pilot valve up or down. The pilot valve is arranged to actuate themain valve in either direction to cause it to open or close its ports bymoving its pistons which are connected to the main valve stem 34. Inthis way the operator has complete control of the main. valve 30 and asthis valve controls the supply or exhaust to the cylinder 12, he isthereby able to cause the plunger and its connected car to move up anddown.

The above is well known in the art and needs no further descriptionhere, and is merely illustrative of one type of construction to whichthe invention may be applied. It has been found difficult in operatingelevators of this type to bring them to rest within a short distance,especially when they are used for high speeds and high rises. Wheneversuch an elevator is used for a high rise, it is found desirable to havethe counterweight 16 of considerable weight to partially balance theweight of the plunger 11, which increases the difficulty of stopping themovement accurately.

Above the stuffing box and cylinder head 13, I place a retarding deviceor brake 40. This retarding device or brake may be supported by somepart of the cylinder head or any stationary fixture near the top of thecylinder 12 and below the lower limit of the travel of the car 10. Thisretarding device or brake is shown clearly in Fig. 2. It

comprises two aws 41 and 42 which are pivoted to a fixed point 43. Thesetwo aws surround the plunger 11. The outer end of jaw 42 is extended andenlarged to form a cylinder 44 in which a piston 45 is arranged to move.A rod 46 is attached to the end of jaw 41 and is connected to the piston45 in the cylinder 44. Between the piston and the end of the cylinder isa spring 47 which, as shown, has a tendency to squeeze the jaws 41 and42 together against the plunger 11. The nut or nuts 48 may be suppliedto regulate the pressure of this spring. A pipe 49 afiords communicationwiththe lower end of the cylinder 44 and when pressure is ad mit-tedthrough this pipe it will counter-act the efiect of the spring 47.

I will now describe the auxiliary valve which is shown in Fig. 3. Itcomprises a cylinder 61 in which a piston 62 is arranged to be moved upor down. WVhen this piston is in its central position it affordscommunication between the pipe 49 and the pipe 63 which may be connectedto the exhaust pipe 32 of the main valve, but whenever it is movedeither up or down by its stem 64 it shuts off the port leading to thepipe 63, and affords communication between the pipe 49 and the pipe 65which may be connected to a course of hydraulic pressure through thepipe 31. The valve stem 64 is shown connected to the arm 35 at 36. Itwill be seen that as the pipe 49 is connected to the cylinder 44 on thebrake or retarding device 40, this cylinder 44 will be opened to theexhaust whenever the pivoted segment is in its central position or willhave pressure admitted to it whenever the pivoted segment is movedeither to one side or the other, and that the position of the auxiliaryvalve will depend on the position of the operating lever 20 in the car.

When the operator desires the car to move and for that reason actuatesthe lever 20 to one side or the other, he thereby through its connectionwhich I have already described causes the main valve to be opened in onedirection or the other and at the same time causes the valve stem 64 ofthe auxiliary valve 60 to be moved up or down. This will cause thelatter to open the ports between the pressure supply and the cylinder 44and will therefore release the pressure of the jaws 41 and 42 upon theplunger and allow it to run freely through them; Now when the operatordesires the car to stop and for that reason brings the operating lever20 back to its central position, he thereby moves the piston 62 of theauxiliary valve 60 back to its central position so that it will shut offthe pressure in the cylinder 4-4 and open the same to the exhaust. Atthe same time the main valve 30 will be moved back to its centralposition to close the ports to the cylinder 12. As the pressure isreleased from cylinder 44 of the retarding device, the spring 47 willapply the jaws 41 and 42 to produce the desired retarding or brakingeflect and cause the car to come to rest quickly. The stop will also bea gentle one without jar or shock, as the pressure of the jaws 41, 42against the plunger 11 is a yielding one produced by the spring 47 whichmay be regulated by the nut 48, and the jaws as they grip the plungerwill tend to destroy all liability of the plunger to vibrate up and downas it comes to rest.

lVhile I have shown the auxiliary valve connected to the supply andexhaust pipes which lead to the main or reversing valve 30 of theelevator, this is but one of the many ways in which it may be used.

I will now describe the part of my inven-' tion which is illustrated inFig. 4. In this case the jaws 70, may be attached to the car'lO. Thesejaws may be pivoted together at 71 and arranged to grip the guides 17,17 The pressure of these jaws on the guides 17 may be obtained by atoggle movement like that illustrated in Fig. 4, in which the rods 72,72 are pressed apart by means of a spring 73. On the ends of the rods,pistons 74, 74 are shown which are surrounded by the cylinder 7 5. Thiscylinder has a pipe 76 lead ing from its outside ends to an auxiliaryvalve 60 like that shown in Fig. 3 and already described, but in thiscase preferably placed upon the car. When pressure is admitted to theends of this cylinder, it will counter-act the eiiect of spring 73 andrelieve the pressure of the jaws 70, 70 from the guides 17 17.

In Fig. 1, I have shown a smallv pipe 63 extending through the plunger11 and leading from the cylinder 12 to the elevator car 10, where it isconnected to the outside ports of the auxiliary valve 60. The centralport of the auxiliary valve 60 is in this case connected to a flexibletube 66 leading away from the car and adapted to take off the dischargeor exhaust from the cylinder 75. The stem 64 of the valve 60 may be inthis case connected to the lever 20 in the car so that whenever theoperator moves this handle to start or to stop the elevator, he therebymoves the piston 62 of the auxiliary valve. The pipe 76 which connectswith the ends of the cylinder 75 is connected to the single central portwhich is shown in one side of the auxiliary valve 60. When the device isarranged as shown in Fig. 4, the pipes are so connected as to have thepipe 76 normally open to the exhaust when the lever 20 is in its centralposition, so thatthe jaws 70, 70 are pressed against the guides 17 17 bymeans of the spring 73 but are released from the guides by means of thepressure which may be led up through the plunger by means of the smallpipe 63 and which passes through the auxiliary valve 60 and the pipe 76to the ends of the cylinder 7 5 whenever the lever is moved to one sideor the other and thereby releases the pressure of the jaws 70, 70 uponthe guides 17, 17. It is evident that the pressure of the jaws 70, 70upon the guides 17 17 may be produced by means of the hydraulic pressureand be released by means of springs. If it is desired to have this done,the cylinder 7 5 may have springs 73, 78 tending to push its pistons 74,74 together and may have a pipe 7 6 leading to the space between thepistons. Such an arrangement is shown in Fig. 5. The operation of thispart of my invention is obvious, for whenever the operator moves thelever 20 in either direction to start the car up, or down, he therebymoves the piston of auxiliary valve 60. The pressure pipe 63 will inthis case be connected to the center port of the auxiliary valve and theexhaust to the outside ports, so that when the operator moves the lever20 away from its central position, the pressure of the jaws 70, 70 onthe guides 17 is thereby released, so that the car may travel freely upor down. Now when the operator brings the lever 20 back to center, thepressure will again apply the jaws 70, 70 to the guides and thereby pro-7 duce the desired braking or retarding effect upon the car.

When a retarding or braking device of this kind is used, a car runningat high speed may be brought to rest quickly and gently within a shortspace of travel. The retarding devices become efiective the moment theoperator moves the controlling device to center, so that they may begintheir retarding ten ency while the main valve is closing. It is alsopossible with this arrangement to use a heavier counterweight than couldbe used without it and it is thereby possible to in crease theefiiciency of the apparatus, as with a heavier counterweight the samecar and load can be lifted with a plunger of smaller diameter or withlower water pressure.

Having described my invention what I claim is:

1. In an elevator, the combination with a car, Jlunger and receivingcylinder, of brake apparatus associated with the plunger, main valveapparatus for controlling the flow of motor-fluid to and from saidcylinder, an auxiliary valve for controlling the application ofmotor-fluid to said brake device independently of said main valveapparatus, additional brake apparatus carried by the car, an additionalvalve for controlling the operation of said additional brake apparatus,and a lever in said car connected to said main valve apparatus, saidauxiliary valve and said additional valve, to secure the operationthereof from a single point.

2. In a hydraulic elevator, the combination of a plunger and a car, aretarding device for the plunger, a retarding device for the car, fluidpressure means -for operating said devices, and a means operable fromthe car for controlling the operation of both the retarding devices thesaid means comprising an element common to the controlling means of bothsaid devices.

3. In a hydraulic elevator, the combination of a car and a plunger forlifting the car, a valve mechanism for controlling the plunger, aretarding device on the car, a retarding device on the plunger, yieldingmeans for actuating the retarding devices in one direction and fluidpressure means for actuating them in the other direction, and auxiliaryvalves for controlling the fluid pressure and a device for operatingsaid valves from the car.

4. In a hydraulic elevator, the combination with a car, plunger andcylinder, of retarding apparatus, and means permitting the transmissionof pressure through said plunger to operate said retarding apparatus.

5. In a hydraulic elevator, the combination with a car, plunger,cylinder and controlling apparatus, of retarding mechanism, and meanscontrolled from the car for permitting the application of fluid-pressurethrough said plunger through said cylinder to operate the retardingmechanism.

6. In a hydraulic elevator, the combination with an elevator car,plunger, cylinder and controlling apparatus, of retarding apparatus, aduct within the plunger, and a valve for controlling the transmission offluid-pressure from said cylinder through said duct to said retardingapparatus to operate the latter.

7. In a hydraulic elevator, the combination of a plunger and a car, aretarding device on the car actuated by fluid pressure, a pressure pipeinside of the plunger and a valve between the retarding device and thepressure pipe for controlling the retarding device.

8. In a hydraulic elevator, tion with a car, plunger, cylinder andchange-valve apparatus, of a retarding device carried with the car,apressure pipe extending longitudinally through the plunger, and a valvebetween the pressure pipe and the retarding device for controlling thefluid-pressure to the latter.

9. In a hydraulic elevator, the combination with a car, plunger,cylinder and change valve apparatus, of a retarding device for the car,a fluid-pressure duct extending through the plunger, a controlling valveconnected between said duct and said retarding device, and means foroperating both the change valve apparatus and the said controlling valvefrom a single point.

10. In a hydraulic elevator, the combination with a car, of a cylinder,a plunger, change-valve apparatus controlling the supply of fluidpressure to the cylinder and the combinaplunger, a hydraulicallyoperated retarding device carried by the car, a hydraulically operatedstationary retarding device, connections from said change-valveapparatus and from said retarding devices to a common source of fluidpressure, and a means operable Within the car for controlling theoperation of the change valve apparatus and the retarding devices thesaid means comprising an element common to the means for operating thechange valve apparatus and the retarding devices.

In witness whereof I have signed my name in the presence of twosubscribing Witnesses.

GRIFFITH JOHN.

lVitnesses O'r'ro T. SMITH, ERNEST W. MARSHALL.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, I). C.

